Doctoral Dissertation Research: The Representation and Processing of Vowel Contrasts

University Of Kansas Center For Research Inc, Lawrence KS

Investigators

Abstract

This doctoral dissertation project uses a series of speech recognition experiments to investigate how the characteristics of vowel sounds are stored in the mind and the role they play in speech comprehension. In order for listeners to comprehend spoken language, the mind must successfully match acoustic information that the listener hears to specific words they know. For example, a native English speaker must be sensitive to the difference in vowel sounds between the words BED and BAD to hear and retrieve the right word in their mind. By comparing the results of experiments in American English with another language, the project analyzes to what extent these vowel characteristics may be stored and processed in a language-specific fashion. As well as making important contributions to the field of psycholinguistics, this research has implications for the teaching of challenging vowel distinctions in the classroom for second language learners, particularly non-native learners of English and native English learners of other languages. In American English, the importance of the distinction between so-called 'tense' versus 'lax' vowel sounds, such as in the words 'beat' versus 'bit', is well known. However, it is unclear how English vowel tenseness is represented in the mind and the consequence this has on spoken word recognition. As for other languages, there is disagreement about whether certain vowel sounds are distinguished by tenseness, as in English, or by other types of vowel characteristics. The project uses a combination of 'cross-modal priming' tasks, in which listeners must recognize one word right after hearing a different one, and 'discrimination' tasks, in which listeners must identify whether two consecutive sounds/words were the same or different. These experiments provide evidence for the way the mind categorizes the characteristics of vowel sounds, as well as how these characteristics lead to the activation of different types of mental representation during speech comprehension: phonological (sound structure), morphological (word structure), and semantic (meaning). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.